The present invention relates to a tyre pressure gauge, and more particularly to a diversified tyre pressure gauge.
A conventional tyre pressure gauge, as shown in FIG. 1, includes a measuring head 1 having a central projection 2 capable of being urged against an air valve of a tyre for passing an air pressure from the tyre, through a through hole 3 in head 1, into a hollow tubular member 4 to axially slide a piston rod 5 in member 4, a housing 6 pivotally mounting therein a sectorial toothed plate 7 meshing with a pinion 8 securing thereon a needle 9 pointing on a scale plate 10 so that needle 9 will point a scale on plate 10 when toothed plate 7 is pivoted by rod 5, a spiral spring 11 for returning rod 5 to the position not actuated by the air pressure, a pawling plate 12 capable of pawling against pinion 8 in order to maintain needle 9 on a position rotated by toothed plate 7, and a push terminal 13 for releasing pinion 8 from being pawled by pawling plate 12 to return pinion 8 to the position not rotated by toothed plate 7.
Such gauge can easily measure the tyre pressure of a 4-wheeled car but cannot conveniently measure the tyre pressure of a bus or a truck, since a 6 or more wheeled vehicle has a relatively wide tyre and inner wheels the tyre pressure of which cannot be easily measured with the relatively short tubular member 4 as in the case happening to a 4-wheeled car. Up to the present, one must crawl into the bottom (under the chassis) of the vehicle if he wants to effectively and accurately measure the tyre pressure of inner wheels of the vehicle. It is therefore tried by the Applicant to deal with this situation.